Olefine-polysulphide plastic



atented Feb. 5, 1.935

UNITED STATES OLEFINE-POLYSULPHIDE PLASTIC Joseph 0. Patrick, KansasCity, M0.

N0 Drawing.

Application June 3, 1929,

Serial No. 368,193

17 Claims.

The present invention relates to improvements in plastic substances, andmore'particularly in the general type of moldable plastic materials ofthe olefine-polysulphide type, such as are described in my priorapplication Serial No. 239,808, filed December 13, 1927.

As disclosed in my prior application, above referred to, theolefine-polysulphide plastics of my invention may be roughly classifiedinto two types; a soft product and a hard product, depending primarilyupon the proportion of sulphur in the polysulphide compound employed inproducing the plastic, and to some extent, upon the method ofproduction. In general, the-best hard plastic, which resemblesvulcanite, bakelite and similar materials in its physical properties, isderived by the use of a polysulphide ranging from a minimum atomicproportion of 51.5 to $2.2 to a maximum of 83.5 to $3.75. In the upperranges, the product resembles in some of its properties the soft type ofplastic, more particularly described in my prior application abovereferred to. The present invention has to do more particularly with thehard type of plastic, which is normally hard and is capable of beingmolded under moderate heat.

- In carrying out the present'invention, a stabilized polysulphidesolution is first prepared. The soluble polysulphides of the alkali oralkaline earth metals may be employed, but in general, the use of thesodium polysulphide is preferred for economic reasons. In preparing thepolysulphide, the selected alkali, for example, caustic soda, in aqueoussolution or dispersion, is caused to react with sulphur and the solutionboiled for a considerable period of time to produce a stabilizedcompound.- For example, asuitable polysulphide solution may be preparedin the following manner:

3 kilograms of caustic soda are dissolved in about 6 liters of water.The required proportion of sulphur to secure the desired proportion ofsul-' phur in the polysulphide, which-may be from 2 to 4 kilograms, isweighed into a container and,

if desired, may be moistened with a liquid such as alcohol, acetone, analcohol-benzol mixture, or the like, which will aid in wetting thesulphur. The greater portion of the alkali solution-is added to thesulphur, say about is added to the sulphur and the mixture boiled untilthe sulphur has substantially completely entered into combination andthe wetting liquid distilled off. The remainder of the alkali solutionmay then be added together with suflicient water to bring the totalvolume of the solution to about 10 liters. The solution at this point isnot stabilized, probably containing both higher and lower polysulphidecomplexes than correspond to the proportion of sulphur present. Thesolution is accordingly heated under a reflux condenser or underpressure in an autoclave for a considerable period of time,-say up to 20hours under atmospheric pressure and for less periodsunder higherpressure. By this treatment, a stabilized material is secured, and thesolution is rapidly filtered, preferably while taking precautions toprevent oxidation. Thus, by proceeding in the above described manner,employing caustic soda and sulphur in the proportions by weight of 3 to2, a solution of polysulphide corresponding to the formula Nazsrs issecured. If the caustic soda and sulphur are in substantially equalproportions by weight, the resulting polysulphide has a formulacorresponding 'to'the polysulphide Nazszxzs. By employing caustic sodaand sulphur in the relative proportions of 48 to 59 a polysulphidecorresponding to Na2S3.e1 is formed, and by using caustic soda andsulphur in the proportions of 40 to 61, a polysulphide corresponding tothe formula Nazsmz, containing some free sulphur, is produced. It isreadily apparent that the same procedure may be employed in producingother soluble polysulphides, such as those of potassium, ammonium,calcium, barium, and the like, for use in the subsequent stages of theprocess. It is apparent that a polysulphide solution which has not beenstabilized may be employed, but is not equally desirable.

A typical plastic of the hard type may be prepared in the followingmanner:

A polysulphide solution, for example, a sodium polysulphide solution,wherein the polysulphide has the empirical formula NazSzQea, is dilutedwith water to reduce its gravity to approximately that of ethylenedichloride. A quantity of ethylene dichloride is then added, preferablysomewhat lessthan the equivalent quantity required for reaction. It isobvious that either an equivalent quantity or an excess of ethylenedichloride may be employed, but it is preferred, for economic reasons,that there be a slight excess of. the polysulphide present. Thus, in thepresent example, 720 grams of ethylene dichloride are employed for each1,000 grams of polysulphide present in solution. The polysulphidesolution and ethylene dichloride are then boiled together under a refluxcondenser until a test of the spent liquid shows the absence ofdissolved sulphides, this point being shown practically by adisappearance of the characteristic polysulphide color. Ap-

' about 350 F., at which decomposition. It is readily apparent -that thebe mixed with any deacid (say, about /2 tains from about uct.

proximately two hours at the boiling point of the mixture (about 170 F.or a little lower) is suflicient. A highly plastic, yellow massaccumulates in the container, and is separated from the liquid. It iskneaded with hot water to remove soluble salts and dried. In a shortwhile, say 24 to 36 hours, it becomes hard, resembling vulcanite,synthetic resin products and celluloid in external appearance. It may bemolded while soft, or after it has become hardened, it may be molded onreheating, beginning to soften at about 200- F. It can'be heated to atemperature of it may be cast, without product, while soft, may siredpigments, fillers or the like. When cast or molded, it fits orreproduces the finest impressions in the mold, and the hard product maybe turned or otherwise readily worked with suitable tools.

The following example illustrates another method of producing the hardplastic product of the present invention, certain features of theprocedure being set forth. and claimed in. my 00- pending applicationSerial No. 369,912, filed June 10, 1929.

A solution of sodium polysulphide of the empirical formula NazSm isprepared, containing about 1'17 grams polysulphide sulphur per 1,000 cc.To each 1,000 cc. of such solution, about 40 grams of calcium oxide,freshly slaked with 200 cubic centimeters of water is added. The mixtureis thoroughly agitated, about 300 cubic centimeters of a water misciblealcohol (ethyl, methyl, isopropyl or the like) is added and l'cubiccentimeters of ethylene dichloride is then added slowly at a rate toprevent the temperature of the mixture rising above about F. Theapparatus in which the mixing is conducted is provided with a refluxcondenser to prevent loss. The plastic product separates out as agreenish-blue, coarsely granular product. This powder is thoroughlywashed with water to remove excess polysulphide and soluble salts, andis finally washed with a. dilute acid solution of sulphuric orhydrochloiic N.) to decompose and remove any residual calcium salts. Inthis washing, the product becomes white, washing liquid by filtration,again washed with water, and dried to constant weight. It is notsoftened or decomposed at the temperature of boiling waterand doesnotdissolve, nor does it swell on contact with carbon disulphide. whenheated to about 270 F., it acquires the consistency of a stiff dough,and can be molded readily. Temperatures of 270 to 325 F. may be employedin molding it. I

The hard type of plastics herein described is secured with polysulphidescontaining such proportions of sulphur that the plastic product con- 63to about 75% of sulphur, the said sulphur being in a combined form. Asstated hereinbefore, theupper limit of sulphur in the hard type ofplastic may vary somewhat in accordance with the method j of separation.Thus, products produced by. the method set forth in the second exampleabove may contain slightly more sulphur, say 1 to 2%, than productsobtained in accordance with the first method, while retaining thecharacteristics of the hard prod- Pigments, and more particularly. the.mineral pigmentsj's'u'ch as iron oxide pigments, Prussian blue, chromegreen, aluminum powder, lead oxide and the like may be incorporated withthe powder reaction body is separated from' the which comprises reactingide with a sodium Nazshs t0 NaaSzmo to secure any desired colorationthereof. Similarly, lakes and rubber dyes may be used to color theproduct. Any desired-fillers may be incorporated therein, such as carbonblack, wood fiour, asbestos fiber, whiting, magnesium carbonate and thelike.

Large quantities of sulphur may be incorporated with the plasticproduct, even in proportions as high as 10 parts of sulphur to 1 of theplastic. The sulphur and the plastic material appear to be mutuallysoluble at molding temperature, and the product is a tough, strong,rubber-like plastic, in which the sulphur apparently shows no tendencyto crystallize. On heating these mixtures of sulphur and plastic fortemperatures around 260 to 270 F. more or less, for some time, say 3 to4 days, rubber-like bodies of a greenish-yellow color are obtained,which are permanently stable. The formation of such bodies is apparentlyaided by the presence of sulphur carriers, such as the various metallicoxides, in proportions as low as 2 to 4% by weight.

Although the connection with the use of ethylene dichloride, it will beunderstood, of course, that other olefine dihalides may be employed,such as ethylene dibromideypropylene dichloride or dibromide, and thelike. The expression "olefine-polysulphide (or product or plastic) inthe claims is intended to mean the material that is obtainable bycausing an olefine dihalide such as these, to react with suchpolysulphides as those mentioned above.

I claim:

1. A normally hard, thermo-plastic olefinepolysulphide reaction bodycontaining from about 63 to about 70% of combined sulphur.

2. A normally hard, thermo-plastic ethylenepolysulphide reaction bodycontaining from about 63 to-70% of combined sulphur.

3. A granular, powdered olefine-polysulphide reaction product containingfrom 63 to 10% of combined sulphur, said powder being thermoplastic attemperatures above the boiling point of water.

4. The method thermo-plastic substance ing upon an olefine dihalide witha soluble polysulphide in which the proportion of sulphur is from 1.5 to3.5 monosulphide.

-5. The method of producing a normally hard, thermo-plastic olefinepolysulphide product upon an olefine dihalide with a sodium polysulphidewithin the range Nflflslj to NazSus in the presence of water.

6. The method of producing a normally hard, thermo plastic olefinepolysulphide product which comprises reacting upon an olefinedihalpolysulphide within the range alcohol.

'7. The method of producing a normally hard, thermo plastic olefinepolysulphide product which comprises reacting upon an ethylene dihalidewith a sodium polysulphide range NazShs to mass. in the presence ofwater and alcohol.

8. The method of producing thermo plastic which comprises reacting uponan ethylene dihalide with a sodium polysulphide within the range Nazsljto Nazsans in the presence of water and freshly slaked calciumhydroxide.

a normally hard,

of producing a normally hard,-

which comprises reacttimes that of the correspondin in the presence ofwater and within the olefine-polysulphide product I 9. The method ofproducing a normally hard, thermo plastic olefine polysulphide productwhich comprises reacting upon an olefine dihalide with a sodiumpolysulphide within the range NaZSLS to Nazssns in the presence of waterand freshly slaked calcium hydroxide.

10. The method of producing a normally hard, thermo plastic olefinepolysulphide product which comprises reacting upon an olefine dihalidewith a sodium polysulphide within the range Na2sl.5 to Nazssxzs in thepresence of water, alcohol and freshly slaked calcium hydroxide.

11. A composition of matter comprising a suflicient amount of a normallyhard, thermo-plastic olefine-polysulphide reaction body containing fromabout 63 to about 70% of combined sulphur to cause the composition to behard.

12. The method of producing a normally hard, thermo-plastic substancewhich comprises reacting upon an olefine dihalide with a solublepolysulphide in which the proportion of sulphur is from 1.5 to 3.5.times that of the corresponding mono-sulphide.

13. The method of producing a normally hard, thermo-plastic compoundwhich comprises reacting with a soluble polysulphide in which theproportion of sulphur is from 1.5 to 3.75 times that of thecorresponding mono-sulphide upon ing upon an olefine dichloride with asoluble polysulphide in which the proportion of sulphur is from 1.5 to3.5 times that of the corresponding mono-sulphide.

1.5. The method of producinga normally hard, thermo-plastic substancewhich comprises reacting upon an ethylene dichloride with a solublepolysulphide in which the proportion of sulphur isfrom 1.5 to 3.5 timesthat of the corresponding mono-sulphide.

16. A composition of matter comprising a pigment and a, sufiicientamount of normally hard, thermo plastic olefine polysulphide reactionbody containing from about 63 to about 70% of combined sulphur to causethe composition to be hard.

17. A composition of matter comprising a dry filler and a sufficientamount of a normally hard, thermo plastic olefine polysulphide reaction.body containing from about 63 to about 70% of combined sulphur to causethe composition to be hard.

JOSEPH C. PATRICK.

